Indicating device



A ri124, 1945. E, A KQREVEC 2,374.439

INDICATING DEVICE Filed Feb. 5, 1941 2 Sheets-Sheet l Edward CZ. .Kreuetr' April 24, 1945. I E, A, KOREVEC 2,374,439

INDICA'I'ING DEVI GE Filed Feb. 3, 1941 2 Sheets-Sheet 2 times.

Patented Apr. 24, 1945 2374,439 c INDICATING mivrcn I by Edward Koret'ec, J oliet, 111,, assignor of onehalf ltoLeo Herkert, J oli et Ill.

ApplicationFebruary 3, 1941,Se1 ial-No. 377,203 1 n 5 Claims. (01.177-351) The invention relates generally'to' indicators or means for giving anindication or measurement at a point or points remote from the thing to be 1 indicated or measured.

The invention has among its objects the pro duction of such a device which is relatively simple in construction, inexpensive to manufacture and very'eflicient for the purposes intended.

Another object of the invention is the produce measuring devices, and more particularly to novel tion of such adevice which may be readily and accuratelycalibrated. a r V A further object of the invention is the produ ctionfof such a device embodying a plur'ality or? fixed} resistances in combination with a potentiometeror other potential varying means to prol vide a device of relatively greatsensitivity and accuracy, in which the fixed resistances maybe so determined as to provide a substantiallyuniform calibration over the range of the instrument.

,A further object of the invention is the production of such a devicejinwhich the potentiometer or the like is automatically connected with the various fixed resistances of the circuit; 3

Another object or the invention is the production of such a device in which a plurality of transmitting or actuating units may be utilizedjand balancedwith' one or more of the receiving-ori indicating units. v r A further object of the invention is'the production of such a device embodying novelmeans for switching the potential varying means into or out means is governed and controlled so that the switchingaction will be fast andpositive thereby insuring correct circuit connections at all Many other objects struction herein shownand described will be obvious to those skilled in the art from thevdisclosure herein given. v r a v gTO; this end my invention consists in the novel ofpjoperative relationship with the resistl A" further object of the invention is pro duction; of such a device in which the switching a and advantages of the con-L on the lined-4 of Fig. 3.

In the past there have been numerous typesoi devices for giving an indication or measurement at a point remote from that at which the actual change or indication was taking place, as for example, devices for measuring the quantity of fluids in tanks and indicating the sam at a point remote from the tanks themselves. Some of thesedevices have utilized various bridge circuits, wherein the particular measurementto be made is based upon the change in potentials in an elec trical resistance circuit this being accomplished mechanically in response to the variations to-be indicated. In the example just given; this could be performed by a float or the likefin the particular tank whose fluid isto be measured. In such devices the actuating means varies the potential i at one side or. the electrical circuit, and to ascertain the amount of change the opposite side of the circuit, which i may include a galvanometer or thelike, is equalizedor balanced therewith at the a i said remote pointwhere the indications are to be observed; this being accomplished by changing the potential of the last mentioned side of the circuit at that point until the potentials of both sides, as indicated upon the galvanometer o'r othersuitableinstrument, are identical. By'observing thevariations in the potential necessary to balance the circuit, an indication may be ob tained as to the changes taking place in the tank,

or other device, depending upon the particular.

thing measured. Generally,.only a single variiable resistor was employed in conjunction with the actuatingmeans as one of the variables in the bridgecircuit. In th present invention the ac tuating means places a potentiometer or other suitable potential varying means across one or umor'e fixed resistances, this operation; due tothe novel mechanical construction employed, being 'efliciently and positively accomplished by the" actuating means.- i r construction, arrangement and combination of parts herein shown and described, and more par-u 'ticularly pointed out in the claim'sr i t n which changes inthetransmitting unit may be In the drawings, wherein like reference *characters indicate like or corresponding parts: g

Fig. l-is adiagrammatic view of acircuit em bodyingthe present invention;

Fi .2 is amen view or the act ann er transmittingunity u Referring to the drawings, and more pa'rticu larly Fig. 1, I designates generally the transmitting portion of the device, actuated by any suit- 1 ablemeans to vary the potential applied to one side of the circuit, and 2 indicates generally the receiving portion of the circuit, by means of observed. it v v r As illustrated in Figs. 2 and 3, the transmitting mechanism comprises a base 3 having a shaft 4 journaled therein. Operatively secured to the Fig. :3 is 'a sectional view {taken approximately 1 on theTline 3-4 of Fig. 2; and v n Fig.4 is a; sectional view taken approximately shaft 4 is a driving wheel 5 which actuates the device. The wheel 5 may be connected with any suitable actuating unit, as for example, such as is shown in my prior Patent Number 2,112,371,

, issued March 29, 1938, which is there utilized 5 for indicating the quantity of fluid'in a tank or other container. However, any other driving means maybe employed to rotate the shaft 4 in response tt-l-changes' iacn particulafi thingf to be measured for indicated? Secured tothe'shaftl0 4 and rotatable therewith is a hollow contact arm designated generally by the numeral 6 aud having a, movable contact 1 maintained in en p gagement with the circular resistance band 8, by

means of a spring 9, the resistance"8 biiig illus 1-5 I respective ends to contacts I to 3| inclusive and putting all-'- the "resistors in-series with one .an-

other: 1, Y. Y

As -shown in- Fig; 3 the contacts 2 I t0 3 l are radially positioned around the side walls-of a bore or'recess1- 32 Positionedin therecess 32 is a;

movable I contact -arm; 33 secured-to arotatable shaft 34 joumaled inrthe-base 3; thearm 33 be; ingconstructed of an insulating m'aterial and-= provided, with a pair of contacts135 and 36 positionedin bores '31 'andvBB -inlthe arms Compres 35 sion spr-ings 39' iurgethe; respective contacts 35 and 36 into engagement with theside; wall of the recess 32 and -the-ycontacts-i l to 3i. As-illuswheel-5 -or other driving member.

, scribed w'iththe exception that the wheel 51s :r-

no possibility of the contact I stopping between the ends of the resistance 8 or the contacts 35 and 36 Stopping between the fixed contacts.

To insure this result novel means are employed for connecting the driving wheel 5 to the shaft 4. Referring to Figs. 3 and 4 it will be seen that the wheel 5 is not rigidly connected to the shaft 4, but is free to rotate relative thereto. A drivingcon'necnbn is obtained by 'secur-ingf a spring membr49 to'the'shaft 4fthespring in the present instance passing through the shaft, and connecting the ends of the spring to the driving If desired a screw 5| or other means may be employed to r vent longitudinal movement between the wheel and shaft. 7 v In operation; when the arm 48 engages the trip pinion 44,'the arm will'stop, the wheel 5 continuing to-ro'tate and will rotate relative the shaft 4 until the. force built u in the spring is-sufiicint 'td 'ovefcon'ie'inertia 'mcmdmg he force appliedbylthe "springjjllt and roller "4 l to the pinion 44f Diiefto the, energy stored in the spring 49fth pinion 44 will remairi'jinfits initial positi sufficientforce is built up, to"a6tiiatth o tactsl ,35, and 33in a sing-1e 'fastsr'iap"actfdna eliminating any'possibility' of the Contact as'siiir -v ing "an "inoperativefpositibnj it will be as parent "that I a definite cohtfbllihg"oi overning actihnof the movable-contacts" novel constructibnempldyed.

The receiving mechanisnfis siliiilar ificoristructidntc the transnnttin mecnanisnrj11st dewit h e suitabl'e frcordiiigdevice? A pointr or" trated in'Figs. t1--. and 'atne; movableicontacts fil ;the"liliefmayfalso 'fbe empleyea to; indicatef'tlie" and-36am sospaeedthat they-will. simultaneously a 40 positionof"the'contacts 35""and"36,'*. For clarity? engag ra pair --ot stationary y contacts-. H Theshaft 34'is'operatiyely connected to a shaft 1 4 lyalso journaled inthe base memben 3, by means 4l--is a-tripz ypinion 44fvvhich, in the present e mstar shape;- i H i H v Attached -at one end toa stud-- carried by the :base 3; is;-a spPing member IIS havingi-a roller 41 pivotally :carriedby ;the free end of *the spring. member, the" roller 4l-be i-ng engageablewith the trip? pinion 44- {to m aintai-n the :latter; in various positions". The relationshipmfithegears 42 and 43-=and'-the pinion 44 lissuch thatya one-sixthrevolution of tha pinion-s44 'willqrotate the arm 33throug-h a -sufiicient arc toFbring the-contacts 35 and 36 in engagement with, the succeeding stationary contacts" 2 I to3l The pinion, 54 .;is I actu'ated by an arm-48-rigidly carried by the shaft, 4s Thusyevery'time thershaft 4 makes -one comg plet'e revolutionitwill advance the pinion fl through one-sixth revolution and therebyrrotate; thearm 33 --to"bri ngz the movable{contacts 35 and 36 into engagement with the succeeding s fixed 5 contacts: a It will beapparent that this construction provi-des a governingraction' of thevrelativemovement' of the trip, pinionu44i andfirollenHose;that-tharm '33-wi-ll at all times abe maintainedginw proper.

relation to the stationary contacts. It is -also desirable qthat; the xarm 33 --be-; moved toaisucceedingposition at the;sametimezthe:con-- tacti -1eaves'one -end='iof-':the resistance and-11cm inr'ig. 'ofthe"drawings,"the'variouspartsofthe receiving mechanism aredes'i'gnated' by thefsame reference numerals-as the 'jcoriesporidih'g parts shafts.- Secured to the -opposite:end:of the-shaft 5 contacts 35 and 36 on thearm 33, so -thatth'e resistanc s *w'illbeplace'dfin mailer with an one oftheres'is'tances i to" 26,? depending npcin the particular contacts -2 'l' to s engaged hymns L movable contacts' 35 and WE-as forexanfpliwhen the contacts 35 and 36 are in the position ill'" trated in Ffg. 1;- theresistancet win beconn' iri parallel with the resistahce Ii -Iii asi'r'iiilarf nail.

Thus it will b seen that the resistance ba'nk 'of' the transmitter and the resis'tance'tbank of the f receive'r= are" con nected in"parallel Alsd conne'c'ted' in parallel i with the two resistance"banksbyfmeans of'Iconductors 58;"59;-and=-'i6 I; is a batter'y:62 orfothr source of potentialz Themovableiicontact -1- of-the transmitter engageable -with the resistance ;8 "-is connected by conductors-53:and64 taagalvanorn-g eter or; other suitable instrument 5 5, the opposite side of the latter being connectedbyrconduc tors 63 and 61 to the corresponding movable conmay be balanced with one another and tact I ofthereceiver, In the embodiment of the invention illustrated inFigs. 2 and 3,, electrical connectionto each of the movablecontacts'! and I: is obtained by theuse of aconductorringfiti electrically connectedto the contact and carried by the shaft .4, the ring being insulated therefrom; by the insulating ringififl. A fixed contact H en-H gageable with the ring 68 ,completes the circuit. a protection to'the instrument B5,, resistances I2 and switches 13a, 13b, and 130 are inserted, in

a fixed position while the arm 6 makes a, complete revolution, therebyeliminating any possibility of the contacts 35 and 36 moving outoi their properposition with respect to the stationary contacts.

series between the instrument 65 and the movable contact 1. l H H The operation of the deviceisas follows: Assuming the device to be connected to a suitable actuating mechanism for measuring the, quantity of liquid in a;tank or other container, the contacts 35 and 36 of the transmitter twill initially be engaged with the stationary contactsp ii-and 122, assuming the tank is emptytwith the contact 1; at its initial or beginning position at the end B of the resistance 8. As the tank bee comes filled, the actuating mechanism will rotate the arm 6 and contact I in a clockwise direction. To ascertain the position of the contact! at any time during its first revolution, the switch13ais,

closed to place the galvanometer or other instrument 65 in series with the arms I, and I, and

thecontrol knob of the receiver is rotated until a minimum indication is obtaineduon thegalvanometer, which would occur when the movable contacts 35', and 36" are engaged with the stationarycontacts 2|" and 22" and thelcontact 1' isinthesame position with respect .to its resistancet' as thecontact l is withrespectto its re-r,

sistance 8. When this balanced condition is reached, the respective elements of the transmit ting unit I and receiving, unitZ are identically l positionedwith respectto oneanother, and :by noting the position of thecontacts. 35., 36, and

thercontact I asindicatedby their; pointers or dials, the amount of liquid lin the tankmay be determined, 'the dials, if desired, being directly;

calibratedin the particular unitvof measurement employed. After the armifixofthe transmitter has completed one revolution, thearmAB carried bytheshaft 4 will trip the pinion. 44 which, by

means of the gears 42 and, will rotate the shaft 34 to bring the movable contacts 35 and 36 in engagement with the contacts22 andf23, re-

spectively, thus putting the resistance Bin paral lel with the resistance l2. In a similar manner each successive revolution of the shaitil, and arm 48 will place the resistance 8 in parallel with the succeeding fixed resistances of the series, and by rotating the control knob or knobs ofthe receiver to a position wherein no current flows through the galvanometer, the transmitter and receiver thereby indicate the desiredresults.

As previously mentioned, the resistances l2 and switches13a, 13b, and 130 are inserted in series with the galvanometer to protect the instrument,

if the contacts 1 and I were at opposite ends of their respective resistances, and then the knob has been rotated to approximatelybalance the receiver with the transmitter, the switches 13b andthen the switch 130 may be closed to provide greater sensitivity and a more accurate adjustment of the contact 1'. I

As previously mentioned with the present, contacts 35 and 36, a snap action isxachieved so that the actual switching will take place at substantially the moment the contact 1 leaves one' end of the resistance 8 and contacts the opposite As illustrated in Fig. 1-, the nductors 54,55,

51 and 59 of the receivingunitrnay belconneeted to suitableswitches 14, whereby the receivermay be operativelyconnected to a plurality of transmitting units. To assureproper calibrationof the receiving unitwith eachof various transmit-j ting units, variable resistors 15 andflfi maybe fplacedin series with the conductors 56-:55 and 56-51 of therespective units, so thatthe trans, mission lines may be, equalizeclwith respect to one another, thusf compensating for, various lengthsof conductors etc which would vary the resistance relationship of thebattery orotherpotential source, and therespective transmitters Such a situation, wouldarise where the several transmitters and,

and receivers to one another.

receivers were positioned at various distances, It

, will be apparent that it is desirable, lin order that accurate results be ,obtained, to havethe bat tery centered with respect to both sides ;oi. the

circuit. l

It will be apparent that by. use, of a plurality of fixed resistances, tom, inclusive, the ca1ibration of the device may be varied tosuit the, particular requirements this being accomplished by properly selecting the resistances of the various fixed resistors, and. by the same means the device may be constructed ofmoreor less uni: form sensitivity throughout its range. Ii' the resistorsfi andfl are held to avery closettolerance ,so that they are of; the sameresistance,

the tolerances of the remaining fixed resistors maybe greater without'appreciably affectinglthe accuracy of the ,device lt will be apparent that,

while themovable contacts BES-Bt and,35-36;;;

areillustrated as engaging adjacent ,fixedcon tacts if. desired the movable contacts could: be spaced farther, apart to engage every second or third stationary contact etc.,; without; affecting the principle involved.

Likewise, if esired the. arniftc could I be omitted in the receiver and the arm fiiicontrolled by. its own dial or knob, independently ;of the contact I.

Similarly, the main of the receiver," cor- 1 responding to the shaft l or the transmitter could be connected to asuitable recording device that would be actuated by the indicating circuit to control the receiver and maintain it in a bali an instrument having improved characteristics struction, employed to rotate the movable conas to sensitivity, etc.

i As previously mentioned, the device may be j employed for use on most any type of equipment wherein a remote indicating instrument is re-- quired.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same Without departing fromthe end of the resistance. Likewise, theroller 4 1 maintains the pinion 44 and associated parts. in l 

